Clamp devices utilizing spring biasing arrangements to provide a closing force on an object being clamped are well known. U.S. Pat. No. 2,482,374 to Ruschmeyer illustrates one such device utilizing a spring biased bolt extended through a pair of eye members mounted on opposite ends of a clamping member. Closure of the clamp compresses the spring against the bolt and urges the eye members toward each other to clamp the object.
U.S. Pat. No. 2,133,060 to Stephens relates to a closure device for pressure cookers, including a flexible band which is drawn together to seal the cover and the cooker body by a toggle arrangement consisting of a handle, a pair of pivotally connected linkage members and a spring contained in a housing formed at one end of the flexible band. Closure of the toggle arrangement compresses the spring and exerts a closing force to seal the cooker. Failure of the spring results in a shift of the flexible band equivalent to the space existing between the turns of the spring which is not sufficient to break the seal and cause loss of pressure existing within the cooker.
U.S. Pat. No. 2,324,356 to Brown discloses a clamping arrangement for use in connection with cover structures for tank truck covers, manhole covers, and the like. The clamping arrangement includes a pivotally mounted arm extending diametrically over the cover, and a closure arrangement having a biasing element for forcing the arm downwardly over the cover and exerting a pressure on the cover when in the closed position.
Other spring biased clamping arrangements are illustrated in U.S. Pat. Nos. 889,042 to Powers and 1,564,837 to Edeborg.